Time'n and Count'n

TABLE OF CONTENTS:

INTRODUCTION

TEST EQUIPMENT FOR TIMING AND COUNTING EXPERIMENTS

Test equipment for detecting a short single pulse and measuring it's width
Pulse generator - 32 microseconds
Pulse generator - 128 microseconds
Pulse generator - 2000 microseconds
Pulse generator - 65280 microseconds
Test equipment for generating a frequency output

USING TIMER 1, TIMER 2 AND THE CAPTURE/COMPARE/PWM (CCP) MODULE

PIC16F870 test circuit
Before we take off
TMR2: 8-bit timer
TMR2 description
How to choose/select mode of operation
Interrupts
TMR2 applications
Free running mode (via TMR2 interrupt)
Free running mode (via period register)

TMR1: 16-bit timer/counter and capture/compare module

TMR1/CCP module simplified
TMR1 description
CCP module - capture mode
CCP module - compare mode
CCP module - PWM mode
How to choose/select mode of operation
T1CON register
CCP1CON register

Interrupts
Reading and writing TMR1
Long time intervals
Controlling the CCP1 pin in compare mode
More than one way to do timing stuff

Timing and counting experiments
Free running output (via TMR1 interrupt)
Event counting (via TMR1)
Count events, read TMR1 contents
Capture TMR1 count when external event occurs
Count events up to predetermined number and generate an output (compare)

Single time interval output (via TMR1 and CCP, compare mode)
Start TMR1, auto end
500 milliseconds
128 microseconds

Free running output (via TMR1 and CCP, compare mode)
Clear TMR1 each cycle
Free running TMR1, add interval value to compare register each cycle

Time measurement (period/interval/time between events)

(via TMR1 read)(interval input via port pin)
(via TMR1 and CCP, capture mode)(interval input via CCP1 pin,
two captures,subtract)

Frequency measurement (via TMR1, gate via TMR0)

External 32,768 Hz watch crystal-based clock for TMR1

Pulse width modulation (PWM) using TMR2 and the CCP module

Analog output - increase/decrease buttons - PWM - 8-bit mode

Duty cycle - 10-bit mode

Analog output - increase/decrease buttons - PWM - 10-bit mode


DESIGNING AND BUILDING YOUR OWN TEST EQUIPMENT

Keypad/LCD user interface

5-digit decimal to 16-bit binary entry program

Using the 5-digit decimal to 16-bit binary entry program
Digital pulse generator
Digital frequency generator
Time interval measurement instrument
Frequency measurement instrument
Creating your own combination signal generator and measurement instrument

APPENDIX A - Program listings vs. page number

APPENDIX B - PICF870 control registers

APPENDIX C - '84 on a board

APPENDIX D - PIC/LCD schematic and code

APPENDIX E - Keypad

APPENDIX F - Using the ICD

APPENDIX G - Sources